CBLN1 and obesity due to melanocortin 4 receptor deficiency: Specific profiles of sphingomyelins (such as SM 18:1/14:0, SM 18:1/16:1, and SM 18:1/18:0) and some ceramides (such as Cer d18:1/16:1, Cer d18:1/18:0, and Cer d18:1/22:0) have been associated to COVID-19 comorbidities such as obesity and cardiovascular-related conditions66.